This makes debugging unnecessarily complex. When the page's JS is not working as expected and you have no clue why we need to set the browser debugger to break on caught exceptions and patiently step through all of them to find something that seems familiar.
If you have some idea that the problem is in that JS code, you're still forced to do weird things like use debugger instructions or resort to printf debugging using console.log.
Ideally, the platform would log the error in Service Center. If that's too much work, at least a console.log where we can see the offending code.